1. Field of the Invention
The present invention relates generally to electronic timepieces and, in particular, to simulated sundials.
2. Description of Related Art
The use of a vertical stick or column to tell time by the shadow cast was known by at least 3500 BCE. The Egyptians developed sundials around 800 BCE. Ahaz, son of Jotham and eleventh king of Judah, developed a sundial in 730 BCE. The sundial was introduced to the Greeks by Anaximander around 520 BCE. In 290 BCE, the Romans captured a sundial in war. For centuries, the sundial has represented modern civilization. In modern times, sundials are primarily used for symbolic value. Sundials have been used for medallions as shown in U.S. Pat. No. Des. 254,733 (Faulkner) and even on watches as shown by U.S. Pat. No. Des. 150,072 (Klaine), U.S. Pat. No. Des. 159,416 (Khan) and U.S. Pat. No. Des. 253,936 (Bova et al.). Each of these designs was, however, intended as an actual, functioning sundial which required the user to correctly orient the sundial wristwatch while outside in the sun. In order to function properly, the gnomon should be inclined at an angle dependent upon the degree of latitude in which it is used. This would mean that each of such watches would only function properly within a narrow range of latitude.
It was not until 1967 that the atomic second replaced the solar second as the time standard. Two years later, Seiko of Japan introduced the first electronic wristwatch. Texas Instruments and Eubauches S.A. together marketed the first liquid crystal digital display timepiece in 1972.
U.S. Pat. No. 4,355,380 (Huguenin et al.) shows a wristwatch with separate displays that are actuated at different times of the day in addition to showing a combination of digital display and a traditional analog watch.